unit counting overhaul, scout order bandwidth fix

- fix scout behaviour sending too many orders (related to idle)
- don't build second fusion immediately after first
- don't built second adv factory immediately after first
- keep track of number of each unit type in ai.nameCount rather than
looping through friendlies
- nukes won't build or stockpile if antinukes are seen in the last
thirty seconds
- check for dangers moved to targethandler, resulting in more consistent
behaviour